Process of making amorphous anhydrous barium hydroxid.



0. ROLLIN. PROCESS OF MAKING AMORPHOUS ANHYDROUS BARIUM HYDBOXID. APPLICATION FILED SEPT. 1, 1911.

1,017,593. Patented Feb. 13,1912.

UNITED STATES PATENT-OFFICE.

CHARLES ROLLIN, Oil NEWCASTLE-UPON-TYNE, ENGLAND. A

PROCESS OF MAKING AMORPHOUS ANHYDBOUS BARIUM HYDROXID.

Specification of Letters Patent.

PatentedFeb. 13,1912.

Original applicationfiled October 8, 1910, Serial No. 586,049. Divided and this application filed September 1, 1911. Serial No. 647,232.

To all whom it may concern.

Be it known that I, C ARLns RoLLIN, B. 80., F. G. S., a subject of the King of Great Britain and Ireland, residing at Newcastleupon-Tyne, England, have invented Improve'ments in or Relating to the Manufacture of Amorphous Anhydrous Barium Hydroxid, of which the following is a specification.

This invention has for object to enable water of crystallization to be removed in an eifective and convenient manner and at a comparatively low temperature from crystallized barium hydroxid in order to produce amorphous anhydrous barium hy-' droxid in a soft porous'condition suitable for use in the manufacture of amorphous barium oxid that can be subsequently converted in an advantageous manner into barium peroxid. For these purposes according to the present invention, water of i crystallization is removed from crystallized barium hydroxid for the purpose mentioned by melting such hydroxid in its own water of crystallization at a comparatively low temperature and under ordinary atmospheric pressure, or practically so, and causing gas that is inert to barium hydroxid to flow over the liquefied hydroxid until the water of crystallization is removed therefrom either wholly or to the desired extent. Theinert gas may be caused to circulate over the liquefied barium hydroxid so that the same gas'is repeatedly used, in which case means are provided for removing therefrom the moisture extracted thereby from the liquefied barium hydroxid, and meansmay also be provided for afterward reheating the gas before again passing it over the hydroxid undergoing treatment.

A mode of carrying out the invention will now be described by way of example and by the aid of the accompanying diagrammatic plan view. According thereto, pure or commercially pure, crystallized'barium hydroxid is melted or liquefied by-heat upon the floor of a closed vessel a through which previously dried inert gas, such as nitrogen or air, that is free from carbondioxid and and in contact with the melted hydroxid so as to evaporate and carry away therewith water of crystallization from the melted hydroxid- The moist airleaving the vessel a may be caused to pass through a counter'current heat exchanger 0 to the fan I) by which it is.

caused toflow through a vessel d containing through a dehydrating'device e, such as a refrigerating. device, wherein the moisture in the air will be removed. The dried and purified air is then caused to fiow through a separate passage 0 or passages in the heat exchanger 0 wherein its temperature will be raised by conduction of heat through walls or tubes o in the heat exchanger from the hot moist air flowingfrom the vessel a through a separate passage or passages in the heat exchanger for example the tubes 0 after which it is caused to flow through a separate heating device f wherein it is raised to the desired temperature and from which it flows back into the vessel a for re-use If desired, the required re-heating of the dried purified air may be effected wholly by the separate heating device f, the heat exchanger 0 being then dispensed with. The several parts of the apparatus are connected together by piping 9 so that the air travels in a closed cycle. A valve such as a check valve at it serves to admit fresh air to the circuit from the external atmosphere to compensate for any leakage that may take place from the circuit. The fluid pressure in the circuit between the delivery of the fan I) and the vessel (1 per square inch above atmospheric pressure will be equal to the weight of a few inches .of water while'there will be a slight reduction in pressure in the circuit between the'vessel a and the suction side of the fan. The vessel a may be heated externally, as by hot gases traversinga fiue nor lines 2' located below its floor or at its sides, in order to melt the crystallized barium hydroxid, or it may be heated only by the passage therethrough ofthe heated air; or. the

vessel may be heated in both of these ways, i

as in the example shown, but care should be taken that the temperature of the vessel and its contents shall not rise above or only slightly above 220 C. At the commencement ofthe operation, the crystallized barlum hydroxid will melt in its water of crystallization and remain for some time at a temperature considerablybelow 220 C. on account of the absorption of heat that takes place during the evaporation of the "water. As the water is driven off and carried away by the heated air, the temperature of the mass will rise and gradually approach that of the heated air until the mass becomes incrusted or solidified, or in a state ready to become solid. At this stage in the operation, the mass is thoroughly broken up by a suit able tool, such as a chisel. The stage at which solidification occurs as stated, represents-the stage at which roughly about one molecule of the original water .of crystallization remains in the solidified portion but parts of the mass that may not have quite reached this might contain more water. The above described heating and dehydrating process is then continued upon the broken up mass at or about or only slightly above 220 C. until practically the whole of the water of crystallization has been removed therefrom and a soft white porous mass of amorphous anhydrous barium hydroxid left behind.

When the mass reaches the higher temperature limit, the heating should be conducted with great care so as to avoid an undue temperature rise, whereby the material of the treatment vessel might be attached and contaminate the product. The vessel in which the crystallized barium hydroxid is melted and dehydrated may be of metal, for example steel. The thickness of the mass of liquefied barium hydroxid dealt with at a time may vary but it may advantageouslybe of about two or three inches. The current of heated air should be caused to flow slowly and continuously over the mass of melted hydroxid and the temperature of the air admitted to the vessel should be maintained, so as to cause slow evaporation of the water and avoid sudden changes of temperature of the mass, or other irregularity of treatment, which would interfere with the obtaining of amphorous anhydrous barium hydroxid of the best quality. The time of evaporationup to the stageof incrustation or solidification, may advantageously be, for example, say about three days for an initial charge of twenty hundredweight of crystallized barium hydroXid. For the further dehydrating treatment a period of about three or four days is ad-.

1. A process for producing anhydrous.

amorphous barium hydroxid from'crystalamorphous barium hydroxid from crystallized barium hydroxid said process consist;

' ing in causing dry inert gaseous fluid to flow over the barium hydroxid while melted in its water of crystallization and until the mass reaches the solidification stage, then breaking up the mass and afterward removing the remaining water of crystallization therefrom while the same is heated to a comparatively low temperature. v

2. A process for producing anhydrous amorphous barium hydroxid from crys tallized barium hydroxid, said process consisting in melting the crystallized barium hydroxid in its Water of crystallization at a comparatively low temperature, causing gaseous fluid heated to a temperature not much exceeding 220 C. and at substantially ordinary atmospheric pressure to fiow slowly over the liquefied barium hydroxid until the mass thereof reaches the solidification stage, then breaking up the resulting mass of partly dehydrated barium hydroxid and afterward slowly removing the remaining water of crystallization therefrom by further heating the mass at a comparatively low temperature the pressure not being substantially below ordinary atmospheric pres-' sure.

3. A process for producing anhydrous amorphous barium hydroxid from. crystallized barium liydroxid, said process consist ing' in inelting the crystallized barium hydroxid in itswater of crystallization at a comparatively low temperature, causing a stream of dry gaseous fluid inert to barium hydroxidto flow continuously over the liquefied hydroxid at a comparatively low temperature, until themass reaches the solidification stage, the gaseous fluid after leaving the hydroxid being dehydrated and then again passed over the barium hydroxid, breaking up the mass of partly dehydrated barium hydroxid and afterward removing the remainder of the water of crystallization therefrom at a comparatively low temperature and .at substantially atmospheric pressure.

4. A process amor hous barium hydroxid from crystallized arium hydroxid, said process consisting in causing dry purified air to flow slowly and at substantially atmospheric pressure. over the barium hydroxid while melted in its water ofcrystallization,removing moisture from the air after it leaves the hydroxid, reheating the air and again passing it over the hydroxid and continuing the operation until the mass reaches the solidification stage, breaking up the solidified mass, and afterward removing the remaining Water of crystallization therefrom while for producing anhydrous heated to a comparatively low temperature and at substantially atmospheric pressure.

5. A process for producing anhydrous.

lized barium hydroxid, said process consisting in causing dried'purified air heated to "atemperature not much exceeding 220 C.

barium hydroxid while melted in its own Water of crystallization whereby it is-solidified the air being dehydrated after leaving the hydroxid, re-heating the air and again passing it over the hydroxid and continuing the operation until the mass reaches the solidification stage, breaking up the solidified mass, similarly heated air again being passed over the mass for a further three or four days to remove the remaining Water of crystallization therefrom substantially as described.

6. A process for producing anhydrous amorphous barium hydroxid from crystallized barium hydroxid, said process consisting in causing dry inert gaseous fluid to' flow over the barium hydroxid While melted in its water of crystallization and until the mass reaches the solidification stage, removing moisture from the hot moist gaseous fluid flowing from the barium hydroxid and causing the dried gaseous fluid to again flow over the barium hydroxid, transmitting heat from the hot moist fluid leaving the barium hydroxid to the dried fluid on its Way back to the barium hydroxid, breaking up the solidified mass of partly dehydrated barium hydroxid and afterward slowly removing the remainder of the Water of crystallization therefrom at substantially atmospheric pressure' Signed at Newcastle-upon-Tyne, England, this eighteenth day of August 1911.

CHARLES ROLLIN.

Witnesses:

WILLIAM STRAKER, W. J. ELSDON. 

